package com.ibeetl.code.ch05;

import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.RunnerException;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;

import java.util.concurrent.TimeUnit;

/**
 * 一个int转string的优化例子
 *
 * @author 公众号 java系统优化
 */
@BenchmarkMode(Mode.Throughput)
@Warmup(iterations = 3)
@Measurement(iterations = 3, time = 1, timeUnit = TimeUnit.SECONDS)
@Threads(1)
@Fork(1)
@OutputTimeUnit(TimeUnit.MILLISECONDS)
@State(Scope.Benchmark)
public class Int2StringTest {

    @Param({"1", "31", "65", "101", "103", "4575"})
    int status = 1;

    @Benchmark
    public String int2String() {
        return String.valueOf(status);
    }

    @Benchmark
    public String int2StringByCache() {
        return CommonUtil.int2String(status);
    }


    public static void main(String[] args) throws RunnerException {
        Options opt = new OptionsBuilder()
            .include(Int2StringTest.class.getSimpleName())
            .build();
        new Runner(opt).run();
    }

    public static class CommonUtil {
        static int cacheSize = 1024;
        static String[] caches = new String[cacheSize];

        static {
            for (int i = 0; i < cacheSize; i++) {
                caches[i] = String.valueOf(i);
            }
        }

        public static String int2String(int data) {
            if (data < cacheSize) {
                return caches[data];
            } else {
                return String.valueOf(data);
            }
        }
    }
}
